應用於薄膜太陽能面板之奈米鋁誘發大晶粒低溫多晶矽薄膜之製備

Nano-Aluminum Induced Crystallization of Larger Grain Low Temperature Poly Silicon Applied for Thin Film Solar Cell

黃健瑋(Chien-Wei Huang)

指導教授 ： 朱孝業

共同指導教授 ： 翁敏航(Min-Hang Weng)

崑山科技大學/工程學院/機械工程研究所/碩士(2008年)

摘要

本研究使用低溫鋁誘發多晶矽(Aluminum induced poly silicon)薄膜以製備薄膜太陽能電池(thin film solar cell)用之矽薄膜。本研究第一部份乃藉由改變鋁薄膜厚度及不同升溫速度，並經由拉曼光譜分析儀(Raman Spectrometer)、薄膜X光繞射儀(X-Ray Thin Film Diffractometer)、霍爾量測(Hall Measurement)等分析低溫鋁誘發多晶矽薄膜之結構、電特性及光學特性。
在本研究中，當升溫速度不同時下，由結果顯示，不同升溫速度下其結晶率差異不大，約為50~60%，但平均晶粒大小卻隨著升溫速度越慢，晶粒越大，從20 nm成長至100 nm。其多晶矽之載子移動率最大值可達1.5 cm2/V-s，而漏電流值範圍約在10-4 ~10 -6 A/cm2。
另外，當選用不同鋁膜厚度來誘發多晶矽薄膜時，其結晶率約為42 ~90%，漏電流值範圍約在10-4 ~10 -13 A/cm2，研究中亦發現當鋁膜厚度小於20 nm時，多晶矽薄膜無法被誘發，此可由拉曼光譜及XRD的結果中可以得到證明。
本研究證實利用奈米鋁誘發技術所成長之薄膜，其晶粒具有晶粒橫向寬度大於縱向深度之優點，有助於提昇薄膜載子移動率，且還可克服高溫製程下薄膜殘留應力大與結晶晶粒過小之缺點，以達到提高薄膜生長速率及縮短薄膜生長時間之目的。

關鍵字

太陽能電池 ； 多晶矽 ； 低溫多晶矽 ； 鋁金屬誘發再結晶

並列摘要

In this paper, we fabricated polycrystalline silicon films with very large grains by the method of nanometer thick aluminum induced crystallization (nano-AIC) on the a-Si:H film deposited by plasma enhanced chemical vapor deposition (PECVD) and analyzed the best function by using different aluminum induced crystallization.
One part of this paper, the effect of annealing ramp-up time of the nano-AIC process on the crystalline volume fraction is discussed. Four different annealing ramp-up time periods, 1, 5, 10, 20 hours, respectively; are fabricated and tested. The results show that crystalline volume fraction calculated is about 50~60% and the average crystalline size grows from 20 to 100 μm under four different annealing ramp-up time. The mobility of the poly-Si film increases with the increase of annealing ramp-up time. The maximum mobility obtained in this paper is about 1.5 cm2/Vs in the case of 20 hours of annealing ramp-up time. The leak current density is between 10-4~10-6 A/cm2,
The other part of this paper , we fabricated AIC specimens with in this five different aluminum thicknesses of 10, 20, 40,80 and 160 nm, respectively. The results show that crystalline volume fraction calculated is about 42~90%. In our analysis, we can see when deposited aluminum thickness varies from 10 to 20 nm, it is not possible to induce poly silicon thin film from the results of, Raman and XRD analyses. Therefore, we can confirm poly silicon will be induced only when aluminum thickness deposition is over 30 nm.

並列關鍵字

solar cells ； poly-crystalline silicon ； low temperature poly silicon ； aluminum induced crystallization

參考文獻

[11]粘志成，製程條件對鋁誘發非晶矽薄膜結晶影響之研究， 碩士論文，崑山科技大學，2005年

[53]凃在根，”鋁金屬誘發結晶法製備多晶矽薄膜與光電特性之研究， 碩士論文，崑山科技大學，2007年

[4]H. Kim, G. Lee, D. Kim and S. H. Lee, “A Study of Polycrystalline Silicon Thin Films as a Seed Layer in Liquid Phase Epitaxy using Aluminum-Induced Crystallization”, Current Applied Physics, Vol. 2, 2002,pp. 129-133.

[5]G. R. Hu, Y. S. Wu, C. W. Chao and H. C. Shih, “Growth Mechanism of Laser Annealing of Nickel-Induced Lateral Crystallized Silicon Films”, Jpn. J. Appl. Phys,Vol. 45, 2006,pp. 21-27

[6]O. Nast, S. Brehme, D. H. Neuhaus and S. R. Wenham, Senior Member, “Polycrystalline Silicon Thin Films on Glass by Aluminum-Induced Crystallization”, IEEE Transactions on Electron Devices, Vol. 46, 1999, pp. 2062-2068